Answer:
Option (B).
Explanation:
The relationship between closely related species can be studied by their evolutionary tree. The two species are closely related if they have similar characteristics and nucleotide sequence.
Species A has the DNA sequence TAGCTTAGGGACGG whereas species B has the DNA sequence TACCTTAGGGACGG. These two species have identical nucleotide sequence with minor differences. Hence, these two species are closely related with each other.
Thus, the correct answer is option (B).
Answer:
The mechanism is natural selection.
Explanation:
Natural selection is the mechanism that these air-breathing fishes have gone through to survive. This mechanism allows species to survive and reproduce due to differences in the phenotypes of every individual in the specie, throughout the time the heritable traits that every individual inherits changes according to the environment and the characteristics of its ancestors.
Carbon atoms can form 4 covalent bonds.
Answer:
D. high fever and sore throat
Explanation:
Human herpesvirus 4 is also known as the Epstein-Barr virus (EBV). Human herpesvirus 4 causes infectious mononucleosis (mono). The virus multiplies first in the epithelial cells and then the released progeny infects the memory B cells. The disease is manifested by sore throat and fever. The fever is mild for the whole day but peaks during the early hours of the evening.
